Both subinterfaces and secondairy interfaces are configurable on a Cisco router. A secondary interface is usualy used we you use up all you ip addresses in an assigned subnet and you ned more addresses. On the other had subinterfaces are used to create logical interfaces, are usualy used to get around the split horizin problem and frame relay or atm networks. Basicaly secondairy address meens one interface with multible addresses, and subinterfaces meen multiple ilogical interfaces. Guy Van Den Bergh wrote: > "subinterfaces" is no cisco speak for aliases. > The Cisco speak for aliases is "secondary" > In Cisco terms you can add an alias to an interface by typing: > ip address <address> <mask> secondary. > Even a third address can be added with this statement. > > The subinterface concept is mainly used for running IP over frame relay > networks. > You can have an interface to a frame relay network, with multiple > subinterfaces for connecting to multiple hosts on the same frame relay > network. > This has to do with the NBMA (non-broadcast multiple access) nature of > frame relay. This basically means that basic ARP does not work on frame > relay. And this is the reason why subinterfaces are really useful on > these networks. > > But I do not fully know this matter in Cisco, nor in Linux speak. > > More information on the Cisco concept of subinterfaces can be found at: > http://www.cisco.com/warp/public/779/smbiz/service/knowledge/wan/subifs.htm > > I guess John wants to know the capabilities of Linux concerning frame > relay, but I don't know anyone with experience on this is on the list. > > The linux equivalent for subinterfaces depends on what you want to do > with it, I guess. > > bert hubert wrote: > > > On Wed, Jan 17, 2001 at 09:32:01PM -0500, John Russo wrote: > > > >> Does Linux support the concept of subinterfaces? If so can anyone point > >> me in the right direction for docs? > > > > > > I think 'subinterfaces' are Cisco speak for IP aliases - if so, yes, try > > this: > > > > ip addr add your.ip.address.here dev eth0 > > _______________________________________________ > LARTC mailing list / LARTC@xxxxxxxxxxxxxxx > http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://ds9a.nl/2.4Routing/
